I'm no expert in Bosch

. Just home hobbyist. Bosch has extensive lineup with confusing naming for those (like me) not working with Bosch

Same product for other region can have different name too.
After looking at the product, I guess it is more to compactness and the lightness of the product. I have no dimension drawing on the 180-Li but I think the 18-2-Li is more compact drill. It is also mentioned that the 180-Li has changeable carbon brushes for easy maintenance and serviceability. Notice the carbon replacement cover on the 180-Li and I can't see one on the 18.2-Li. It is not saying that the 18-2-Li has no carbon but perhaps it is build inside the motor; meaning you replace the whole motor assembly. This keeps the size compact I believe. I still like the old fashioned replaceable carbon on the 180-Li though.
Let see if others who has extensive experience in power tool especially these Bosch tool owners has to comment on this price difference.

18-2 is an older model, back then semua benda packed with 18-2, butnow Bosch keluar the 180, with lower 1814 charger, and 1.5AH battery. The 1.5ah battery is significantly cheaper than the 2.0ah battery with gauge.
You mahu cheap, just get the 180, no wrong there. Rather than pay for the 18-2, might as well get the 18VEC.
I have an GSR18-2 (bukan GSB yerr), all these time ingat its inferior, big, heavy, unbalanced, but then tengok the 180...and also the newer 18V-30 BL motor, tidak jadi tukar, stick with my compact (suprisingly) 18-2.
I got the GSR18-2 with the GBH 18-LI for rm950 shipped, with 1860 and 4+2AH battery. The GSB18-2 price of RM780 is seriously mind boggling.
Oh, 18-2 is PRO range (12M Warranty), the 180 is Contractor range (6M Warranty). Bosch MY devised this weird classification...in the UK can get 3Y warranty.
Makita saja laaaa
Thank you bros for the help & detailed insights. I've settled with GSB 18V-EC.